Binder solutions containing fugitive metal precursors for use in additive manufacturing processes

Abstract

To provide a binder solution that maintains green strength and provides improved brown strength to a printed area during a print post-process.SOLUTION: A green body part contains multiple layers of particulate materials, a dissipative metal precursor of not less than 0.5% and not more than 5% by weight and a thermoplastic binder of not less than 0.5% and not more than 3% by weight based on the total weight of the green body part. The dissipative metal precursor contains a salt selected from the group consisting of nickel chloride, iron chloride, nickel formate, and combinations thereof, and an organic metallic compound. The thermoplastic binder contains a first polymer strand including a first functional group and a second polymer strand including a second functional group that is different from and complementary to the first functional group. The thermoplastic binder couples the particulate materials of the multiple layers of particulate materials. The green body part has a three-point bending strength of 5 MPa or greater as measured according to ASTM B312-14.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 029,957, filed May 26, 2020, entitled "Binder Solutions Comprising Fugitive Metal Precursors for Use in Additive Manufacturing," which is incorporated herein by reference in its entirety.

[0002] This disclosure relates to additive manufacturing processes. More particularly, this disclosure is directed to binder solutions including fugitive metal precursors for use in additive manufacturing processes. [Background technology]

[0003] Additive manufacturing, also known as 3D printing, is a process in which material is deposited layer by layer to form an article. Binder jetting is an additive manufacturing technique based on using a binder to bond particles of powder to form a three-dimensional object. Specifically, the binder is jetted sequentially onto layers of powder in the build volume, where the powder and binder layers adhere to each other to form the three-dimensional object. Depending on the application, the printed part is suitable for the end use.

[0004] In other applications, post-processing such as debinding and powder sintering may be required to convert the printed three-dimensional part into a finished part. Therefore, it is desirable for the printed part to have a green strength suitable for handling (e.g., transport, inspection, powder removal) and a Brownian strength suitable for minimizing distortion during the debinding / sintering process. However, binder solutions previously available for binder-jet 3D printing do not provide the Brownian strength necessary to prevent distortion and damage to the printed part during post-printing processes. Summary of the Invention [Problem to be solved by the invention]

[0005] Therefore, there is a need for an alternative binder solution that maintains green strength and provides improved brown strength to printed parts during post-print processing. [Means for solving the problem]

[0006] Various embodiments of the binder solution disclosed herein meet these needs by including a dissipative metal precursor that fills voids and provides contact and bridging between particles in the powder bed prior to sintering of the particulate material, thereby improving the Brownian strength and overall stiffness of the printed part. Increasing the density of the article reduces shrinkage and increases the strength of the printed part, thereby reducing cracking and distortion.

[0007] According to a first aspect A1, the binder solution may include 0.5% to 40% by weight, based on the total weight of the binder solution, of a fugitive metal precursor; a thermoplastic binder including one or more thermoplastic polymer strands; and a solvent in which the fugitive metal precursor and the thermoplastic binder are dissolved.

[0008] A second aspect A2 includes a binder solution according to the first aspect A1, wherein said binder solution comprises ≧1 wt % and ≦20 wt % of fugitive metal precursors, based on the total weight of the binder solution.

[0009] A third aspect A3 includes a binder solution according to the first aspect A1 or the second aspect A2, wherein the fugitive metal precursor is selected from the group consisting of alkaline earth metals, transition metals, post-transition metals, metalloids, rare earth metals, and the like. and combinations thereof.

[0010] A fourth aspect A4 includes a binder solution according to any one of the first aspect A1 to the third aspect A3, wherein the fugitive metal precursor includes an organometallic compound, and the organometallic compound includes ferrocene, cobaltocene, iron pentacarbonyl, or a combination thereof.

[0011] A fifth aspect A5 includes the binder solution of any of the first aspect A1 to fourth aspect A4, wherein the fugitive metal precursor includes a salt, and the salt includes a compound selected from the group consisting of carboxylates, nitrates, sulfates, carbonates, formates, chlorides, halides, derivatives thereof, and combinations thereof.

[0012] A sixth aspect A6 includes a binder solution according to the fifth aspect A5, wherein the salt includes nickel chloride, iron chloride, nickel formate, copper chloride, silver nitrate, nickel nitrate, copper nitrate, aluminum nitrate, magnesium chloride, barium nitrate, barium chloride, titanium nitrate, or a combination thereof.

[0013] A seventh aspect A7 includes a binder solution according to any one of the first aspect A1 to the sixth aspect A6, wherein each of the one or more thermoplastic polymer strands has an average molecular weight of 1000 g / mol or more and 50,000 g / mol or less.

[0014] An eighth embodiment A8 includes a binder solution according to any one of the first embodiment A1 to the seventh embodiment A7, wherein each of the one or more thermoplastic polymer strands is selected from the group consisting of polyvinyl alcohol (PVA), polyamide, polyacrylamide (PAAm), polymethyl methacrylate (PMMA), polyvinyl carbonate, derivatives thereof, and combinations thereof.

[0015] The ninth aspect A9 includes the binder solution according to any one of the first aspect A1 to the eighth aspect A8, and the viscosity of the binder solution is 1 cP or more and 40 cP or less.

[0016] According to a tenth aspect A10, a method for manufacturing a part may include the steps of depositing a layer of particulate material on a work surface; selectively applying a binder solution to the layer of particulate material in a pattern representing a layer of the part; repeating the deposition of the layer of particulate material and the selective application of the binder solution to form multiple layers of particles coated with the binder solution; and evaporating the solvent to harden the multiple layers of particles and applied binder solution to form a green body, wherein the binder solution includes a thermoplastic binder including 0.5% by weight or more and 40% by weight or less of a fugitive metal precursor, based on the total weight of the binder solution, one or more thermoplastic polymer strands, and a solvent, wherein the fugitive metal precursor and the thermoplastic polymer strands are dissolved in the solvent.

[0017] An eleventh aspect A11 includes the method according to the tenth aspect A10, wherein curing the printed binder solution includes heating the multiple layers of the applied particulate material including the binder solution at a temperature of 40°C or more and 80°C or less.

[0018] A twelfth aspect A12 includes methods according to the tenth aspect A10 or the eleventh aspect A11, wherein the fugitive metal precursor comprises a salt selected from the group consisting of carboxylates, nitrates, sulfates, carbonates, formats, chlorides, halides, derivatives, and combinations thereof.

[0019] A thirteenth aspect A13 includes the method according to any one of the tenth aspect A10 to the twelfth aspect A12, wherein the particulate material includes a metal particulate material, and the metal particulate material is selected from the group consisting of nickel alloys, cobalt alloys, cobalt chromium alloys, titanium alloys, aluminum-based materials, and tungsten. alloy, stainless steel alloy, or a combination thereof.

[0020] A fourteenth aspect A14 includes the method according to the thirteenth aspect A13, including heating the green body part above a first temperature in an oxygen-free environment to sinter at least a portion of the thermoplastic binder, sintering at least a portion of the fugitive metal precursor to form necked regions between the particulate material to form a brown body part, and heating the brown body part to a second temperature or greater to sinter the particulate material.

[0021] A fifteenth aspect A15 includes the method of any of tenth aspect A10 to twelfth aspect A12, wherein the particulate material comprises a ceramic particulate material, the ceramic particulate material comprising alumina, aluminum nitride, zirconia, titania, silica, silicon nitride, silicon carbide, boron nitride, or a combination thereof.

[0022] According to a sixteenth aspect A16, a green part may include a plurality of layers of particulate material; 0.5 wt. % to 5 wt. % of a fugitive metal precursor, based on the total weight of the green part; and 0.5 wt. % to 3 wt. % of a thermoplastic binder, based on the total weight of the green part, the thermoplastic binder including one or more thermoplastic polymer strands, the thermoplastic binder binding the particulate material of the plurality of layers of particulate material, and the green part having a three-point flexural strength measured according to ASTM B312-14 of 1.0 kPa or greater.

[0023] A seventeenth aspect A17 includes the green body part according to the sixteenth aspect A16, wherein the fugitive metal precursor comprises a salt selected from the group consisting of carboxylates, nitrates, sulfates, carbonates, formates, chlorides, halides, derivatives thereof, and combinations thereof.

[0024] An eighteenth aspect A18 includes a green body part according to the sixteenth aspect A16 or the seventeenth aspect A17, wherein the particulate material includes a metal particulate material, and the metal particulate material includes a nickel alloy, a cobalt alloy, a cobalt chromium alloy, a titanium alloy, an aluminum-based material, a tungsten alloy, a stainless steel alloy, or a combination thereof.

[0025] A nineteenth aspect A19 includes the green body part according to the sixteenth aspect A16 or the seventeenth aspect A17, wherein the particulate material includes a ceramic particulate material, the ceramic particulate material including alumina, aluminum nitride, zirconia, titania, silica, silicon nitride, silicon carbide, boron nitride, or a combination thereof.

[0026] A twentieth aspect A20 includes a green body part according to any one of sixteenth aspects A16 to A19, wherein each of the one or more thermoplastic polymer strands is selected from the group consisting of polyvinyl alcohol (PVA), polyamide, polyacrylamide (PAAm), polymethyl methacrylate (PMMA), polyvinyl carbonate, derivatives thereof, and combinations thereof.

[0027] Additional features and advantages of the embodiments disclosed herein are set forth in the detailed description which follows, and in part will be readily apparent to or discernible by those skilled in the art from the following detailed description and the accompanying drawings, including by practicing the disclosed embodiments as described herein.

[0028] It is to be understood that both the foregoing general description and the following detailed description describe various embodiments, and are intended to provide an overview or framework for understanding the nature and character of the claimed subject matter. The accompanying drawings are included to provide a further understanding of the various embodiments, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present invention and are not to be construed as limiting the present invention. The various embodiments are illustrated and, together with the description, serve to explain the principles and operation of the claimed subject matter. [Brief explanation of the drawings]

[0029] [Figure 1] 1 is a plot showing strength versus temperature curves for a part formed using a conventional binder solution and a part formed using an exemplary binder solution including a fugitive metal precursor according to one or more embodiments described herein. [Figure 2] FIG. 1 is a flow diagram of an embodiment of a method for producing a consolidated part via an additive manufacturing process using an example binder solution including a fugitive metal precursor according to one or more embodiments described herein. [Figure 3] FIG. 3 is a block diagram of one embodiment of an additive manufacturing apparatus used to manufacture a consolidated part according to the method of FIG. [Figure 4] 3 is a schematic diagram of an embodiment of a layer of particulate material from which a consolidated part resulting from operation of the method of FIG. 2 is produced. [Figure 5] 3 is a schematic illustration of particulate material after deposition of a binder solution according to the method of FIG. 2. [Figure 6] FIG. 3 is a schematic illustration of particulate material after debinding according to the method of FIG. 2. [Figure 7] FIG. 3 is a schematic illustration of particulate material after sintering according to the method of FIG. 2. [Figure 8] 3 is a photograph of a sample formed using a comparative binder solution by the method of FIG. 2. [Figure 9] 9 is a photograph of the sample of FIG. 8 after sintering according to the method of FIG. 2. [Figure 10] Distortion analysis of the sample in Figure 9. [Figure 11] 3 is a photograph of a sample formed using an exemplary binder solution including a fugitive metal precursor according to one or more embodiments described herein according to the method of FIG. 2. [Figure 12] 12 is a photograph of the sample of FIG. 11 after sintering according to the method of FIG. 2. [Figure 13] Distortion analysis of the sample in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0030] Reference will now be made in detail to various embodiments of fugitive metal precursor binder solutions for use in additive manufacturing processes.

[0031] In particular, various embodiments of the fugitive metal precursor binder solution include from 0.5% to 40% by weight of the fugitive metal precursor, based on the total weight of the binder solution, thermoplastic binder, and solvent. Various embodiments of binder solutions including fugitive metal precursors, and the use of such binder solutions in additive manufacturing processes, are described herein with specific reference to the accompanying drawings.

[0032] Ranges can be expressed herein as up to "about" one particular value, and / or to "about" another particular value. When such a range is expressed, another embodiment includes the one particular value and / or the other particular value. Similarly, when values ​​are expressed as approximations, by use of "about," it will be understood that the particular value forms another embodiment. The beginning and end points of a range each have significance relative to the other point (the end point and the beginning point), and each have a significance independent of the other point.

[0033] Directional terms used herein, e.g., up, down, right, left, front, back, top, bottom, etc., are made solely with reference to the figures as drawn and are not intended to imply absolute orientations.

[0034] Unless otherwise expressly stated, any method described herein should not be construed as requiring that its steps be performed in a particular order, nor is it intended that any specific direction be required. Accordingly, method claims may not necessarily require the order in which their steps should actually be followed. If a claim or specification does not recite a particular order of steps, or if any apparatus claim does not actually recite an order or orientation for individual components, or if the claim or specification does not recite a particular order or orientation for the apparatus components, no order or orientation is intended to be inferred in any way. This holds true for all possible implicit bases for interpretation, including the arrangement of steps, the flow of operations, the logic of the order or direction of components, the plain meaning derived from grammatical organization or punctuation, and the number or type of embodiments described in the specification.

[0035] As used herein, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise; thus, for example, reference to "a" element includes aspects having two or more such elements unless the context clearly dictates otherwise.

[0036] As used herein, the term "fugitive metal precursor" refers to a metal salt or organometallic compound that decomposes upon debinding and / or sintering, resulting in the production of a metal, metal oxide, metal carbide, or metal nitride and the burnout of the organic and inorganic functional groups of the metal salt or organometallic compound.

[0037] As used herein, the term "thermoplastic binder" refers to a binder that includes one or more thermoplastic polymer strands that have functional groups that interact through weak non-covalent forces (e.g., interactions, bonds) to bond or otherwise connect the respective thermoplastic polymer strands to one another.

[0038] As used herein, the term "weak non-covalent forces" refers to hydrogen bonds, ionic bonds, Van der Waals forces, etc., having a bond or force of 1 kcal / mol or more and 7 kcal / mol or more. Point.

[0039] As used herein, the terms "standard temperature and pressure" and "STP" refer to a temperature of 0°C and a pressure of 101.325 kPa.

[0040] As used herein, the term "jetable" refers to the ability to jet a binder solution, for example, from a printer head. A binder solution can be considered "jetable" if all polymers and additives are solubilized in the binder solution and the binder solution has a viscosity of 1 to 40 centipoise (cP).

[0041] As discussed herein, the parameter "viscosity" of the binder solution is measured using a rheometer according to ASTM E3116.

[0042] As used herein, the term "debinding" refers to heating a green body part above a first temperature such that thermal decomposition of the thermoplastic binder into small oligomers occurs and at least a portion of the thermoplastic binder is removed, thereby forming a brown body part.

[0043] As used herein, the term "sintering" refers to heating the brown body part to a second temperature or above to remove remaining portions of the thermoplastic binder (e.g., oligomeric residues and pyrolysis by-products formed during debinding) and to solidify the particles of the powder bed, thereby forming a solidified part.

[0044] As used herein, the term "decomposition" refers to the reduction of fugitive metal precursors to metal only and the burn-off of organic and inorganic functional groups of the fugitive metal precursors during debinding and / or sintering.

[0045] As used herein, the term "necked region" refers to a localized deformation of the metallic material between adjacent grains of particulate material.

[0046] As used herein, the term "green body part" refers to a printed part that has not undergone a heat treatment to remove the thermoplastic binder.

[0047] As used herein, the term "brown body part" refers to a printed part that has undergone a debinder heat treatment to remove at least a portion of the thermoplastic binder.

[0048] As discussed herein, the part parameters "green strength" and "brown strength" are measured using a three-point bending strength test according to ASTM B312-14.

[0049] In additive manufacturing processes involving binder jetting, a binder solution is jetted from a printer head onto layers of powder in succession to bond the powder particles and form a printed three-dimensional part. As discussed above, in embodiments, subsequent processing (e.g., debinding and sintering) may be required to convert the printed three-dimensional part into a consolidated part. Therefore, it is desirable for the printed part to have a green strength suitable for handling (e.g., transfer, inspection, depowdering) and a Brownian strength suitable for minimizing distortion during post-printing processes. This reduces the occurrence of pre-consolidation warpage and part failure, thereby increasing manufacturing throughput.

[0050] However, conventional binder solutions containing thermoplastic binders generally do not provide the Brownian strength necessary to prevent distortion and damage to printed parts during post-printing processes. Specifically, the strength of green parts is provided by the binder solution, with some contribution from particle friction and mechanical interlocking of particles. The strength provided by the binder solution is due to weak non-covalent bonding forces (e.g., similar to polymer binders) formed between thermoplastic polymer strands. When the green part is heated to remove the thermoplastic binder and form the Brownian part (i.e., before the particles are sintered together), the mechanical strength of the printed part (i.e., Brownian strength) depends on inter-particle friction and mechanical interlocking, which is limited in the relatively large, roughly spherical particles commonly used to form powder beds (e.g., metal particles). Low Brownian strength can lead to part warping and mechanical failure.

[0051] Therefore, various embodiments of the binder solution described herein include a dissipative metal precursor that fills voids between particles in the powder bed and provides contact and bridging between particles in the powder bed prior to sintering of the particulate material, thereby improving the Brownian strength and overall stiffness of the printed part. Furthermore, increasing the density of the article reduces shrinkage, increases the strength of the printed part, and reduces cracking and distortion.

[0052] Referring now to FIG. 1 , as shown by curve A, a part formed using a conventional binder solution containing a thermoplastic binder exhibits poor Brownian strength (BS) after the green part is heated to remove the thermoplastic binder but before sintering the particulate material (ST). In contrast, as shown by curve B, a part formed using a binder solution containing a fugitive metal precursor according to embodiments disclosed herein exhibits improved Brownian strength (BS) as the green strength (GS) decreases after the green part is heated to remove the thermoplastic binder but before sintering the particulate material. The Brownian strength is achieved when debinding is performed in a conductive atmosphere, where the fugitive metal precursor decomposes to form reduced metal, resulting in an improvement in the overall stiffness of the Brownian part. This improved stiffness imparts Brownian strength, replacing the green strength after debinding. Decomposition of the fugitive metal precursor may occur over a wider range of temperatures depending on the decomposition characteristics of the fugitive metal precursor.

[0053] As described above, the binder solutions described herein may include a fugitive metal precursor, a thermoplastic binder, and a solvent. When provided in the binder solution, the fugitive metal precursor decomposes at the lower temperature of the debinding process and can bind the particulate material prior to sintering, thereby providing strength to the Brownian part. The strength provided by the fugitive metal precursor allows for the formation of fine features and / or large parts in the consolidated part. For example, in parts including cantilevered portions, such as overhangs, poor Brownian strength can lead to the collapse or cracking of the cantilevered portion because the inter-particle friction that holds the printed part together before sintering does not support the weight of the cantilevered portion. However, the fugitive metal precursor may decompose during the debinding process, allowing for in-situ metal formation, which provides stiffness and strength to the printed part after all the thermoplastic binder is sintered by contacting and crosslinking the particulate material prior to sintering, thereby improving the overall strength and stiffness of the printed part.

[0054] In embodiments, the fugitive metal precursor is selected from the group consisting of alkaline earth metals (i.e., elements in Group II of the periodic table), transition metals (i.e., elements in Groups III-XII of the periodic table), post-transition metals (i.e., aluminum, gallium, indium, tin, thallium, lead, and bismuth), metalloids (i.e., boron, silicon, germanium, arsenic, antimony, and tellurium), rare earth metals (i.e., scandium, yttrium, and lanthanides), and combinations thereof. In embodiments, the fugitive metal precursor is an organic solvent-soluble organometallic compound, such as, but not limited to, ferrocene, cobaltocene, iron pentacarbonyl, or combinations thereof. In embodiments, the fugitive metal precursor is a compound selected from the group consisting of salts, such as carboxylates, nitrates, sulfates, carbonates, formates, chlorides, halides, derivatives thereof, and combinations thereof. Examples of suitable water / organic solvent soluble salts include, but are not limited to, nickel chloride, iron chloride, nickel formate, copper chloride, silver nitrate, nickel nitrate, copper nitrate, nickel carbonate, silver carbonate, silver perchlorate, silver halide, nickel nitrate, nickel sulfate, nickel oxalate, nickel oxalate dehydrate, ammonium molybdate tetrahydrate, aluminum nitrate, magnesium chloride, barium nitrate, barium chloride, titanium nitrate, and combinations thereof. Other fugitive metal precursors are also contemplated. In embodiments, the fugitive metal precursor is completely soluble in the solvent at STP.

[0055] In embodiments, the binder solution includes 0.5 wt.% or more and 40 wt.% or less of fugitive metal precursor, based on the total weight of the binder solution. In embodiments, the amount of fugitive metal precursor in the binder solution may be 0.5 wt.% or more, 1 wt.% or more, or 2 wt.% or more. In embodiments, the amount of fugitive metal precursor in the binder solution may be 40 wt.% or less, 30 wt.% or less, 25 wt.% or less, 20 wt.% or less, 15 wt.% or less, 12 wt.% or less, 10 wt.% or less, 8 wt.% or less, or 6 wt.% or less. For example, the amount of fugitive metal precursor in the binder solution may be 0.5 wt% to 40 wt%, 0.5 wt% to 30 wt%, 0.5 wt% to 25 wt%, 0.5 wt% to 20 wt%, 0.5 wt% to 15 wt%, 0.5 wt% to 12 wt%, 0.5 wt% to 10 wt%, 0.5 wt% to 8 wt%, 0.5 wt% to 6 wt%, 1 wt% to 40 wt%, 1 wt% to 30 wt%, 1 wt% to 20 wt%, 0% by weight or less, 1% to 15% by weight, 1% to 8% by weight, 1% to 6% by weight, 2% to 40% by weight, 2% to 30% by weight, 2% to 25% by weight, 20% to 15% by weight, 2% to 12% by weight, 2% to 8% by weight, or 2% to 6% by weight, or any and all subranges formed by any of these endpoints.

[0056] The binder solution further includes at least one binder that provides strength to the green body part by binding the particulate material and its layers together after a curing step in which some or all of the binder solution's solvent is evaporated. Suitable binders include, but are not limited to, thermoplastic binders, thermosetting binders, and non-polymeric binders such as waxes and sugars (glucose, fructose, derivatives thereof, or combinations thereof).

[0057] In embodiments, the binder comprises a thermoplastic binder comprising one or more thermoplastic polymer strands. In embodiments, the thermoplastic binder is selected from a class of thermoplastic polymers that generally decompose into lower molecular weight oligomers, carbon dioxide, and water without requiring the presence of oxygen. Thus, in embodiments, the thermoplastic binder can be cleanly and easily removed during debinding and sintering to produce a consolidated part that is substantially free of the thermoplastic binder and decomposition products (e.g., char and metal oxides).

[0058] In embodiments, the one or more thermoplastic polymer strands include a first polymer strand. In embodiments, the first polymer strand includes at least a first functional group. The functional group of the first thermoplastic polymer strand may include, but is not limited to, a hydrogen bond donor, a hydrogen bond acceptor, a negatively charged group, a positively charged group, or a combination thereof. In embodiments, the first functional group is part of the backbone of the first thermoplastic polymer strand. In embodiments, the first functional group of the first polymer strand is complementary to a functional group of a second polymer strand of the thermoplastic binder, facilitating non-covalent bonding of the first and second polymer strands. For example, in embodiments, the first functional group is selected from a hydroxyl group, a carboxyl group, an amine, a thiol, an amide, or other suitable functional group that allows for weak non-covalent bonding of the first and second polymer strands.

[0059] In water-soluble embodiments, the first polymer strands include polymers such as, but not limited to, polyvinyl alcohol (PVA), polyamide, polyacrylamide (PAAm), derivatives thereof, and combinations thereof. In organic solvent-soluble embodiments, the first polymer strands include polymethyl methacrylate (PMMA), polyvinyl carbonate, derivatives thereof, and combinations thereof. In embodiments, the first polymer strands have an average molecular weight (Mw or weight average) of 1,000 g / mol or more and 50,000 g / mol or less. In embodiments, the first polymer strands have an average molecular weight of 1,000 g / mol to 50,000 g / mol, 1,000 g / mol to 30,000 g / mol, 1,000 g / mol to 25,000 g / mol, 1,000 g / mol to 23,000 g / mol, 5,000 g / mol to 30,000 g / mol, 5,000 g / mol to 25,000 g / mol, 5,000 g / mol to 23,000 g / mol, 7,000 g / mol to 30 ... 0g / mol to 25,000g / mol, 7,000g / mol to 23,000g / mol, 9,000g / mol to 50,000g / mol, 9,000g / mol to 30,000g / mol, 9,000g / mol to 25,000g / mol Below, 9,000g / mol to 23,000g / mol, 13,000g / mol to 50,000g / mol, 13,000g / mol to 30,000g / mol, 13,000g / mol to 25,000g / mol, 13,000g or more 23,000g / mol or less, 23,000g / mol or more50, 000g / mol or less, 23,000g / mol to 30,000g / mol, 23,000g / mol to 25,000g / mol, 25,000g / mol to 50,000g / mol, 25,000g / mol to 30,000g / mol, 30,000g / mol to 50,000g / mol, or any of these ends All subranges formed from points.

[0060] The first polymer strands may be present in the binder solution at from 1 to 15 wt%, from 1 to 10 wt%, from 1 to 7 wt%, from 3 to 15 wt%, from 3 to 10 wt%, from 3 to 7 wt%, from 5 to 15 wt%, from 5 to 10 wt%, from 5 to 7 wt%, or any subrange formed from any of these endpoints, based on the total weight of the binder solution. In embodiments, the first polymer strands may be at least 80 wt% soluble in the solvent at STP.

[0061] In embodiments, the one or more thermoplastic polymer strands further comprise a second polymer strand. In water-soluble binder embodiments, the second polymer strand comprises at least a second functional group different from the first functional group of the first polymer strand. The functional group of the second thermoplastic polymer strand may include, but is not limited to, a hydrogen bond donor, a hydrogen bond acceptor, a negatively charged group, a positively charged group, or a combination thereof. In embodiments, the second functional group is part of the backbone of the second thermoplastic polymer strand. In embodiments, the second functional group of the second polymer strand is complementary to the first functional group of the first polymer strand of the thermoplastic binder, facilitating non-covalent bonding of the first and second polymer strands. For example, in embodiments, the second functional group may be selected from a hydroxyl group, a carboxyl group, an amine, a thiol, an amide, or other suitable functional group that allows for weak non-covalent bonding of the first and second polymer strands.

[0062] In water-soluble binder embodiments, the second polymer strands include, but are not limited to, polymers such as polyacrylic acid (PAA), polymethacrylic acid (PmAA), derivatives thereof, and combinations thereof. In embodiments, the second polymer strands have an average molecular weight (Mw, or weight average molecular weight) of 100 g / mol to 10,000 g / mol. For example, the second polymer strands can have an average molecular weight of 100 g / mol to 10,000 g / mol, 100 g / mol to 5000 g / mol, 500 g / mol to 10,000 g / mol, or 500 g / mol to 5000 g / mol, or any and all subranges formed from any of these endpoints.

[0063] The second polymer strands are present in the binder solution at from 1 to 10 wt%, from 1 to 9 wt%, from 1 to 8 wt%, from 1 to 7 wt%, from 1 to 6 wt%, or from 1 to 5 wt%, based on the total weight of the binder solution, or any and all subranges formed from any of these endpoints. In embodiments, the second polymer strands may be at least 80 wt% soluble in the solvent at STP.

[0064] In an embodiment of the water-soluble binder, the first polymer strands comprise a different polymer than the second polymer strands, hi an embodiment, the first polymer strands comprise polyvinyl alcohol (PVA) and the second polymer strands comprise polyacrylic acid (PAA).

[0065] The first and second polymer strands are included in the binder solution in an amount that allows bonding between the first and second polymer strands so that the green body part has sufficient green strength to withstand handling during post-printing processes. In embodiments, the weight ratio of the first polymer strands to the second polymer strands is greater than or equal to 3:1 and less than or equal to 7:1. For example, The weight ratio of the marr strands can be 3:1, 4:1, 5:1, 6:1, or 7:1. In embodiments, the binder solution includes polyvinyl alcohol (PVA) and polyacrylic acid (PAA) in a weight ratio of 3:1 or greater and 4:1 or less.

[0066] In embodiments, the one or more thermoplastic polymer strands further comprise a third polymer strand. The third polymer strand includes, but is not limited to, polyoxazoline, polyvinyl methyl ether maleic anhydride (PVME-MA), polyvinylpyrrolidone (PVP), polyvinyl methyl ether-maleic anhydride (PVME-MA), and organic solvent-soluble polymers such as polymethyl methacrylate (PMMA), polybutyl methacrylate (PBMA), polycarbonate (PC), polyethylene (PE), derivatives thereof, and combinations thereof. In embodiments, the third polymer strand has an average molecular weight (Mw, i.e., weight average molecular weight) of 100 g / mol or more and 10,000 g / mol or less. For example, the third polymer strand can have an average molecular weight of from 100 g / mol to 10,000 g / mol, from 100 g / mol to 5000 g / mol, from 500 g / mol to 10,000 g / mol, or from 500 g / mol to 5000 g / mol, or any and all subranges formed from any of these endpoints.

[0067] In embodiments, the third polymer strand is present in the binder solution at from 1 to 10 wt%, from 1 to 9 wt%, from 1 to 8 wt%, from 1 to 7 wt%, from 1 to 6 wt%, from 1 to 5 wt%, or any subrange formed from any of these endpoints, based on the total weight of the binder solution. In embodiments, the third polymer strand may be at least 80 wt% soluble in the solvent at STP.

[0068] In addition, the binder solution further includes at least one solvent. The solvent can be aqueous or non-aqueous, depending on the thermoplastic binder selected and other additives that may be present in the binder solution. The solvent may be generally non-reactive (e.g., inert) so as not to react with the particulate material, the thermoplastic binder, or any other additives that may be present in the binder solution. In embodiments, at least a portion of the solvent may readily evaporate during deposition of the binder solution onto the layer of particulate material prior to thermal curing, facilitating bonding of the particulate material. In embodiments, the solvent may be, but is not limited to, water, methylene chloride, chloroform, toluene, xylene, mesitylene, anisole, 2-methoxyethanol, butanol, 1-methoxy-2-propanol, 2-butoxyethanol, ethylene glycol, ethylene glycol butyl ether, diethylene glycol, tetrahydrofuran (THF), methyl ethyl ketone (MEK), trichloroethylene (TCE), or a combination thereof. In embodiments, the solvent may be present in an amount of from 1 to 85 wt%, from 1 to 75 wt%, from 1 to 50 wt%, from 1 to 25 wt%, from 1 to 10 wt%, from 10 to 85 wt%, from 10 to 75 wt%, from 10 to 50 wt%, from 10 to 25 wt%, from 25 to 85 wt%, from 25 to 75 wt%, from 25 to 50 wt%, from 50 to 85 wt%, or from 50 to 75 wt%, based on the total weight of the binder solution, or any subrange formed from any of these endpoints.

[0069] In an embodiment, the binder solution includes nickel nitrate, polyvinylpyrrolidone (PVP), and 2-methoxyethanol.

[0070] In an embodiment, the binder solution includes ferrocene, polystyrene, and a chlorinated solvent such as benzene, toluene, or dichloroethane.

[0071] In an embodiment, the binder solution includes nickel chloride, polyvinyl alcohol (PVA), polyacrylic acid (PAA), and water.

[0072] In an embodiment, the binder solution includes nickel formate, polyvinyl alcohol (PVA), polyacrylic acid (PAA), and water.

[0073] In an embodiment, the binder solution includes iron chloride, polyvinyl alcohol (PVA), polyacrylic acid (PAA), and water.

[0074] In an embodiment, the binder solution includes iron formate, polyvinyl alcohol (PVA), polyacrylic acid (PAA), and water.

[0075] In embodiments, the viscosity of the binder solution meets printer head specifications to ensure jettability of the binder solution. In embodiments, the binder solution has a viscosity of from 1 cP to 40 cP, from 1 cP to 35 cP, from 1 cP to 25 cP, from 1 cP to 20 cP, from 2 cP to 40 cP, from 2 cP to 35 cP, from 2 cP to 30 cP, from 2 cP to 25 cP, or from 2 cP to 20 cP, or any and all subranges formed from any of these endpoints. To achieve such viscosities, in embodiments, a rheology modifier may be included in the binder solution as an optional additive.

[0076] Thus, in embodiments, the binder solution may optionally include one or more additives that adjust the jettability and viscosity of the binder solution to facilitate deposition of the binder solution into the layer of particulate material. Optional additives include surfactants, diluents, viscosity modifiers, dispersants, stabilizers, or any other additives. In embodiments, the surfactant may be ionic (e.g., zwitterionic, cationic, anionic) or nonionic, depending on the properties of the thermoplastic binder and / or the particulate material. In embodiments, the surfactant may be polypropyloxy quaternary ammonium chloride (e.g., VARIQUAT® CC available from Evonik Industries). 42 NS), oligomers of hexanoic acid (e.g., HYP available from Kuroda Advanced Materials) ERMER® KD2), alkylene esters of fatty acids and alkylamines, 2-[4-(2,4-trimethylpentan-2-yl)phenoxy]ethanol (e.g., TRITON® X-100 available from The Dow Chemical Company), polyoxyethylene (80) sorbitan monooleate (e.g., TWEENTM 80 available from Kuroda America), polyoxyethylene-23-lauryl ether (e.g., For example, BRIJ™ L23 available from Kuroda America, Inc. may be included, which may include sodium dodecyl sulfate (SDS), hexadecyltrimethylammonium bromide (CTAB), dodecyltrimethylammonium bromide (DTAB), or a combination thereof.

[0077] Referring now to FIG. 2, a method of producing a consolidated part via additive manufacturing using a binder solution according to embodiments described herein is shown at 10. To facilitate discussion of aspects of method 10, please also refer to FIG. 3, which is a block diagram illustrating an embodiment of an additive manufacturing apparatus 30 that may be used to perform method 10. Method 10 begins at block 12 by depositing a layer 22 of particulate material 24 onto a work surface (e.g., creating a powder bed), as shown in FIG. 4. In embodiments, layer 22 may have a thickness 26 of at least 10 microns (μm) and at most 200 μm. The particulate material 24 used to print a part may vary depending on the type and end use of the part.

[0078] In particular, the particulate material 24 may be a nickel alloy (e.g., Inconel 625, Inconel 718, Rene'108, Rene'80, Rene'142, Rene'195, and R ene'M2, Marm-247), cobalt alloys (e.g., Hans 188, L60 The metal particulate material may include a metallic particulate material such as aluminium alloys (F1, F1X, F1X4, F1X5, F1X4 ...

[0079] In embodiments, the particulate material 24 may include a ceramic particulate material such as alumina, aluminum nitride, zirconia, titania, silica, silicon nitride, silicon carbide, boron nitride, or a combination thereof. In embodiments, the ceramic particulate material may include particles having a particle size distribution of 0.1 μm to 100 μm. Such particulate materials may be used to print ceramic articles for use in, for example, but not limited to, the medical and transportation industries.

[0080] 2, in block 14, following deposition of particulate material 24, method 10 continues by selectively depositing a binder solution onto portions of layer 22 according to a pattern. For example, the binder solution may be selectively printed onto layer 22 of particulate material 24 using a printer head operated by a controller based on a CAD design that includes a representation of the layer of the consolidated part to be printed.

[0081] For example, as shown in FIG. 3 , the additive manufacturing apparatus 30 may be a binder jetting printer that selectively deposits a binder solution onto the layer 22 in accordance with the operations of block 14 ( FIG. 2 ). In embodiments, the binder jetting printer 30 may include a work surface 32 that supports the layer 22 of particulate material 24, a reservoir 34 that contains a binder solution 36, and a printer head 38 fluidly coupled to the reservoir 34. The printer head 38 selectively deposits the binder solution 36 onto the layer 22 of particulate material 24 to print the binder solution 36 onto the layer 22 in a pattern that represents a layer of the consolidated part being printed. In embodiments, the binder jetting printer 30 may include a control system 42 for controlling the operation of the binder jetting printer 30. The control system 42 may include a distributed control system (DCS) or any fully or partially automated computer-based workstation. In embodiments, control system 42 may be any suitable device employing a general-purpose computer or an application-specific device, and may generally include a memory circuit 44 that stores one or more instructions for controlling the operation of binder-jetting printer 30. Memory circuit 44 may store a CAD design representing the structure of the aggregate part to be printed. The processor may include one or more processing devices (e.g., microprocessor 46), and memory circuit 44 may include one or more tangible, fixed, machine-readable media that collectively store instructions executable by the processor to control the operations described herein.

[0082] The binder solution 36 deposited on the layer of material may be any one of the binder solution embodiments described herein, including, for example, a fugitive metal precursor 36a and a thermoplastic binder 36b. In embodiments, the particular binder solution 36 is selected based at least in part on the particulate material 24 used to form the layer 22. For example, in embodiments, the fugitive metal precursor 36a of the binder solution 36 and the particulate material 24 may include one or more of the same elements. For example, in embodiments where the particulate material 24 is a metal particulate material including nickel, the fugitive metal precursor 36a of the binder solution 36 may include nickel or a nickel-based compound. As another example, in embodiments where the particulate material 24 is a metal particulate material including a nickel alloy, a cobalt alloy, a cobalt chromium alloy, a titanium alloy, an aluminum-based material, a tungsten alloy, a stainless steel alloy, or the like, the binder solution 36 may include nickel chloride or a nickel-based compound. The binder solution 36 may include fugitive metal precursors 36a in the form of salts including aluminum nitrate, iron chloride, nickel formate, copper chloride, silver nitrate, copper nitrate, etc. As another example, the particulate material 24 may be a ceramic particulate material including alumina, aluminum nitride, zirconia, silica, silicon nitride, silicon carbide, or boron nitride, and the binder solution 36 may include fugitive metal precursors 36a in the form of salts including aluminum nitrate, magnesium chloride, barium chloride, titanium nitrate, etc.

[0083] 5, after deposition, the binder solution 36 at least partially coats the outer surface 54 of the particulate material 24, thereby creating binder-coated particles. As discussed herein, upon curing, the thermoplastic binder of the binder solution 36 binds the particulate material 24 according to the pattern of the binder solution 36 printed on the layer 22 of the particulate material 24 to form a layer of the green body part 60.

[0084] In method 10, the operations of blocks 12 and 14 can be repeated to continue building up alternating layers of the part until the desired number of layers has been printed. The thermoplastic binder of binder solution 36 binds each successive layer 22 together and provides a degree of strength (e.g., green strength) to the printed part, ensuring that the structural integrity of the printed green part 60 is maintained during post-printing processes (e.g., transfer, inspection, de-powdering). That is, the green strength provided by the thermoplastic binder of binder solution 36 maintains the bond between the particulate material 24 in layer 22 and the block (e.g., resist) and prevents delamination of layer 22 during handling and post-printing processing of the green part 60.

[0085] Following deposition of layer 22 and printing of binder solution 36, as described in blocks 12 and 14 of FIG. 2 , method 10 continues in block 16 with curing binder solution 36 to form green body part 60. For example, as described above, binder solution 36 is a mixture of a fugitive metal precursor, a thermoplastic binder, and a solvent. While some of the solvent in binder solution 36 may evaporate during deposition (e.g., printing) of binder solution 36, some amount of solvent may remain within layer 22 of particulate material 24. Thus, in embodiments, binder solution 36 may be heat cured at a suitable temperature to evaporate any remaining solvent in printed layer 22 and enable efficient bonding of printed layer 22, thereby forming green body part 60. Heat may be applied to the printed part using an IR lamp and / or a heated plate, or by placing the printed part in an oven. In embodiments, curing the binder solution 36 includes heating the printed layer 22 at a temperature of from 25°C to 100°C, from 30°C to 90°C, from 35°C to 80°C, or from 40°C to 70°C, or any subrange or all subranges formed from any of these endpoints.

[0086] In embodiments, after the part is cured to remove the solvent, the thermoplastic binder present in the green part 60 binds the particulate material 24 of the multiple layers 22 together. In embodiments, the amount of fugitive metal precursor in the green part 60 is, based on the total weight of the green part 60, between 0.5 and 5 wt %, between 0.5 and 4.5 wt %, between 0.5 and 4 wt %, between 0.5 and 3.5 wt %, between 0.5 and 3 wt %, between 0.5 and 2.5 wt %, between 0.5 and 2 wt %, between 0.5 and 1.5 wt %, between 1 and 5 wt %, between 1 and 4.5 wt %, between 1 and 4 wt %, between 1 and 3.5 wt %, or between 1 and 3 wt %. or less, 1% by weight or more and 2.5% by weight or less, 1% by weight or more and 2% by weight or less, 1.5% by weight or more and 5% by weight or less, 1.5% by weight or more and 4.5% by weight or less, 1.5% by weight or more and 4% by weight or less, 1.5% by weight or more and 3.5% by weight or less, 1.5% by weight or more and 3% by weight or less, 1.5% by weight or more and 2.5% by weight or less, 2% by weight or more and 5% by weight or less, 2% by weight or more and 4.5% by weight or less, 2.5% by weight or more and 4% by weight or less, 2.5% by weight or more and 3.5% by weight or less, 3% by weight or more and 5% by weight or less, 3% by weight or more and 4.5% by weight or less, 3% by weight or more and 4% by weight or more, or any of these endpoints In embodiments, the amount of thermoplastic binder in the green body part 60 is, based on the total weight of the green body part 60, from 0.5 wt.% to 3 wt.%, from 0.5 wt.% to 2.5 wt.%, from 0.5 wt.% to 2 wt.%, from 0.5 wt.% to 1.5 wt.%, from 1 wt.% to 3 wt.%, from 1 wt.% to 2.5 wt.%, from 1 wt.% to 2 wt.%, from 1.5 wt.% to 3 wt.%, from 1.5 wt.% to 1.5 wt.%, or even from 2 wt.% to 3 wt.%, or any and all subranges formed from any of these endpoints. In embodiments, the particulate material comprises substantially all of the remaining percentage after adding the amount of fugitive metal precursor and the amount of thermoplastic binder in the green body part 60. In embodiments, the particulate material used to form the green body part 60 is weighed to determine the weight percentages of particulate material, thermoplastic material, and fugitive metal precursor in the green body part 60. Next, a green part 60 is printed using a thermoplastic binder without the dissipative metal precursor and weighed. The weight of the particulate material is subtracted from the weight of the green part printed with the thermoplastic binder to determine the weight of the thermoplastic binder. Next, a green part 60 is printed using the thermoplastic binder and the dissipative metal precursor and weighed. The weight of the green part printed with the thermoplastic binder is subtracted from the weight of the printed green part 60 with the thermoplastic binder and the dissipative metal precursor to determine the weight of the dissipative metal precursor. The weight percentage of each component can then be calculated.

[0087] To prepare the green body part 60 for post-printing processes such as removal and sintering after curing, unbound particles (e.g., particulate material 24 not bound by binder solution 36) may be removed from the powder bed.

[0088] After curing, the green body part 60 may undergo an optional drying step (not shown) to remove residual solvent and / or other volatile materials that may remain within the green body part 60. For example, the green body part 60 may be dried in a vacuum, an inert atmosphere (e.g., nitrogen (N), or It may be dried under argon (Ar) or in air at slightly elevated temperature or room temperature.

[0089] In embodiments, the green body part 60 has a strength of 5 MPa or more, 5.5 MPa or more, 6 MPa or more, 6.5 MPa or more, 7 MPa or more, 7.5 MPa or more, 8 MPa or more, 8.5 MPa or more, 9 MPa or more, 9.5 MPa or more, or 10 MPa or more.

[0090] Following the curing of the binder solution 36 to form the green body part 60, the method 10, in block 18, heats the green body part 60 to a first temperature or above to remove at least a portion of the thermoplastic binder (e.g., debinding) and form a brown body part 62. In embodiments, the decomposition temperature of the fugitive metal precursors of the binder solution 36 is lower than the first temperature. As such, during debinding, at least a portion of the fugitive metal precursors of the binder solution 36 decompose, resulting in in-situ metal formation of a metallic material 64. For example, as shown in FIG. 6 , during the debinding process, the fugitive metal precursors of the binder solution 36 may decompose into metallic material 64 with nanometer-scale dimensions. The metallic material 64 has a very high surface area-to-volume ratio, which may provide a high driving force for sintering. As the metallic material 64 sinters, it may promote the formation of “bridges,” such as constricted regions of the metallic material 64, between adjacent particles of the particulate material 24. The constricted regions of metallic material 64 bridging the particulate material 24 thereby increase the brown strength of the brown body part 62 after the thermoplastic binder has burned out but prior to consolidation (i.e., sintering) of the particulate material 24. In embodiments, the first temperature is from 60° C. to 700° C., from 70° C. to 600° C., from 75° C. to 500° C., even from 80° C. to 400° C., or any and all subranges formed from any of these endpoints.

[0091] In embodiments, heating the green body part 60 above the first temperature may include heating the green body part 60 in an oxygen-free environment (e.g., in a vacuum chamber / inert atmosphere) or in air. In metal embodiments, the debinding agent may be, for example, nitrogen (N), It can be performed in an oxygen-free environment, such as, but not limited to, argon (Ar), other inert gas, or under vacuum. In ceramic embodiments, debinding may be performed in air or any other environment appropriate for the particular material being processed.

[0092] In embodiments, the brown body part 62 may have a strength of 1 MPa or greater, 1.5 MPa or greater, 2 MPa or greater, 2.5 MPa or greater, 3 MPa or greater, 3.5 MPa or greater, 4 MPa or greater, 4.5 MPa or greater, or 5 MPa or greater.

[0093] 2 concludes in block 20 by heating the Brown body part 62 above a second temperature to sinter the particulate material 24, thereby forming a consolidated part 70. In embodiments, the second temperature is equal to or greater than the temperature at which the particulate material 24 sinters. Thus, by heating the Brown body part 62 above the second temperature, the particulate material 24 sinters with the metallic material 64 (FIG. 6), thereby forming a metallic phase 72 as shown in FIG. In embodiments, the second temperature is from 75° C. to 1500° C., from 75° C. to 1450° C., from 75° C. to 1400° C., from 100° C. to 1500° C., from 100° C. to 1450° C., from 100° C. to 1400° C., from 200° C. to 1500° C., from 200° C. to 1450° C., from 200° C. to 1400° C., from 300° C. to 1500° C., from 300° C. to 1450° C., from 300° C. to 1400° C., from 400° C. to 1500° C., from 400° C. to 1450° C., from 400° C. to 1400° C., or any subrange formed from any of these endpoints. In embodiments, the nickel alloy, cobalt alloy, or stainless steel alloy may decompose at a temperature of from 400° C. to 900° C.

[0094] In embodiments, heating the Brown body part 62 above the second temperature may include heating the Brown body part 62 in an oxygen-free environment (e.g., a vacuum chamber / inert atmosphere). In metal embodiments, sintering may be performed using nitrogen (N), argon (Ar), or another inert atmosphere. In ceramic embodiments, sintering may be carried out in air or any other environment suitable for the particular material being processed.

[0095] In an embodiment, debinding of block 18 and sintering of block 20 shown in FIG. 2 in method 10 occurs in a single step.

[0096] Although the various embodiments described herein are described with reference to method 10, it should be understood that the binder solution embodiments described herein can be used with a variety of methods known and used by those skilled in the art. In particular, curing and sintering can be accomplished in a number of different ways, at a number of different steps, and at a number of different locations. [Example]

[0097] The embodiments will be further clarified by the following examples, which should be understood as not limiting the above-described embodiments.

[0098] One comparative and four exemplary binder solutions were prepared for analysis. The formulations of the comparative and exemplary binder solutions are shown in Table 1 (in weight percent).

[0099] [Table 1]

[0100] Corresponding printed part samples were prepared using each of the binder solutions of Comparative Example 1 and Examples 1 and 2. Following sintering, each sintered sample was subjected to elemental analysis (LECO Instrument: CS844 C The results of the elemental analysis were shown in Table 2.

[0101] [Table 2]

[0102] As shown in Table 2, the samples formed using the binder solutions of Examples 1 and 2 had similar carbon and oxygen contents after sintering as the sample formed from the binder solution of Comparative Example 1. Without wishing to be bound by theory, it is believed that the addition of the metal salt NiCl2 to the binder solution This suggests that the addition of SiO2 did not have a negative effect on the chemical composition of the sintered parts (e.g., charring).

[0103] Additionally, two samples formed using the binder solution of Comparative Example 1 and two samples formed using the binder solution of Example 1 were spanned across two setter blocks, as shown in Figure 8 (Comparative Example 1) and Figure 11 (Example 1). The samples were formed by filling a rectangular silicone mold with a dissipative metal precursor powder and adding a thermoplastic binder (e.g., via a dropper) to create a wet block. The silicone mold was placed in a conventional oven and cured at 200°C for 1 hour. After cooling, the sample block was removed from the mold. The samples were placed in an oven and sintered at 1390°C for 6 hours. As shown in Figures 9 and 10, the samples formed using the binder solution of Comparative Example 1 sagged due to gravity during sintering. As shown in Figures 12 and 13, the samples formed using the binder solution of Example 1 showed less sagging. Without wishing to be bound by theory, it is believed that the reduced sagging of the samples formed using the binder solution of Example 1 compared to the samples formed using the binder solution of Comparative Example 1 may be due to the presence of fugitive metal precursors (e.g., NiCl) in the binder solution of Example 1.

[0104] Further aspects of the invention are provided by the subject matter of the following sections:

[0105] 1. A solvent solution comprising a binder solution comprising 0.5 wt. % or more and 40 wt. % or less of a fugitive metal precursor based on the total weight of the binder solution, a thermoplastic binder comprising one or more thermoplastic polymer strands, and a solvent, wherein the fugitive metal precursor and the thermoplastic binder are dissolved in the solvent.

[0106] 2. The binder solution of any preceding claim, wherein the binder solution comprises 1% by weight or more and 20% by weight or less of fugitive metal precursor, based on the total weight of the binder solution.

[0107] 3. Dissipative metal precursors include alkaline earth metals, transition metals, post-transition metals, semimetals, and rare earth metals. 10. The binder solution of any preceding claim, wherein the metal is selected from the group consisting of: metals, iron, iron-containing oxides, iron-containing tungsten ...

[0108] 4. The binder solution of any preceding claim, wherein the fugitive metal precursor comprises an organometallic compound, the organometallic compound comprising ferrocene, cobaltocene, iron pentacarbonyl, or a combination thereof.

[0109] 5. The binder solution of any preceding claim, wherein the fugitive metal precursor comprises a salt, the salt comprising a compound selected from the group consisting of carboxylates, nitrates, sulfates, carbonates, formates, chlorides, halides, derivatives thereof, and combinations thereof.

[0110] 6. The binder solution of any preceding claim, wherein the salt comprises nickel chloride, iron chloride, nickel formate, copper chloride, silver nitrate, nickel nitrate, copper nitrate, aluminum nitrate, magnesium chloride, barium nitrate, barium chloride, titanium nitrate, or a combination thereof.

[0111] 7. The binder solution of any preceding claim, wherein each of the one or more thermoplastic polymer strands has an average molecular weight of 1000 g / mol or more and 50,000 g / mol or less.

[0112] 8. The binder solution of any preceding claim, wherein each of the one or more thermoplastic polymer strands is selected from the group consisting of polyvinyl alcohol (PVA), polyamide, polyacrylamide (PAAm), polymethyl methacrylate (PMMA), polyvinyl carbonate, derivatives thereof, and combinations thereof.

[0113] 9. The viscosity of the binder solution is 1 cP or more and 40 cP or less, as described in any of the above items. of binder solution.

[0114] 10. A method for manufacturing a part, comprising: depositing a layer of particulate material on a work surface; selectively applying a binder solution to the layer of particulate material in a pattern representing a layer of the part, wherein the binder solution comprises 0.5% by weight or more and 40% by weight or less of a fugitive metal precursor based on the total weight of the binder solution, a thermoplastic binder comprising one or more thermoplastic polymer strands, and a solvent, wherein the fugitive metal precursor and the thermoplastic binder are dissolved in the solvent; repeating the steps of depositing the particulate material and selectively applying the binder solution to form multiple layers of particulate material containing the applied binder solution; and curing the applied binder solution in the multiple layers of particulate material containing the applied binder solution to evaporate the solvent, thereby forming a green body part.

[0115] 11. The method of any preceding claim, wherein curing the applied binder solution comprises heating the multiple layers of particulate material containing the applied binder solution at a temperature of 40°C or higher and 80°C or lower.

[0116] 12. The method of any preceding claim, wherein the fugitive metal precursor comprises a salt selected from the group consisting of carboxylates, nitrates, sulfates, carbonates, formates, chlorides, halides, derivatives thereof, and combinations thereof.

[0117] 13. The method of any preceding claim, wherein the particulate material comprises a metal particulate material, the metal particulate material comprising a nickel alloy, a cobalt alloy, a cobalt chromium alloy, a titanium alloy, an aluminum-based material, a tungsten alloy, a stainless steel alloy, or a combination thereof.

[0118] 14. The method of any preceding claim, wherein the method further comprises heating the green body part at or above a first temperature in an oxygen-free environment to remove at least a portion of the thermoplastic binder and sinter at least a portion of the fugitive metal precursor such that the sintered fugitive metal precursor forms necked regions of metal material between the particulate material to form a brown body part; and heating the brown body part to or above a second temperature to sinter the particulate material, thereby forming a consolidated part.

[0119] 15. The method of any preceding claim, wherein the particulate material comprises a ceramic particulate material, the ceramic particulate material comprising alumina, aluminum nitride, zirconia, titania, silica, silicon nitride, silicon carbide, boron nitride, or a combination thereof.

[0120] 16. A green body part comprising a plurality of layers of particulate material, and 0.5% to 5% by weight of a fugitive metal precursor, based on the total weight of the green body part, and 0.5% to 3% by weight of a thermoplastic binder, based on the total weight of the green body part, wherein the thermoplastic binder comprises one or more thermoplastic polymer strands, and wherein the thermoplastic binder binds the particulate material of the plurality of layers or parts of the particulate material, and wherein the green body part comprises a three-point flexural strength of 5 MPa or greater, measured in accordance with ASTM B312-14.

[0121] 17. The green body part of any preceding claim, wherein the fugitive metal precursor comprises a salt selected from the group consisting of carboxylates, nitrates, sulfates, carbonates, formates, chlorides, halides, derivatives thereof, and combinations thereof.

[0122] 18. The green body part of any preceding claim, wherein the particulate material comprises a metal particulate material, the metal particulate material comprising a nickel alloy, a cobalt alloy, a cobalt chromium alloy, a titanium alloy, an aluminum-based material, a tungsten alloy, a stainless steel alloy, or a combination thereof.

[0123] 19. The green body part of any preceding claim, wherein the particulate material comprises a ceramic particulate material, the ceramic particulate material comprising alumina, aluminum nitride, zirconia, titania, silica, silicon nitride, silicon carbide, boron nitride, or a combination thereof.

[0124] 20. The green body part of any preceding claim, wherein each of the one or more thermoplastic polymer strands is selected from the group consisting of polyvinyl alcohol (PVA), polyamide, polyacrylamide (PAAm), polymethyl methacrylate (PMMA), polyvinyl carbonate, derivatives thereof, and combinations thereof.

[0125] The above embodiments, and their features, are exemplary and may be provided alone or in any combination with any one or more features of the other embodiments provided herein without departing from the scope of the disclosure.

[0126] It will be apparent to those skilled in the art that various modifications and variations can be made to the present disclosure without departing from the spirit and scope of the disclosure. Thus, the present disclosure is intended to cover the modifications and variations of this disclosure provided they come within the scope of the appended claims and their equivalents.

[0127] The following are supplementary claims of the present application. (Additional note 1) Dissipativeness of 0.5% by weight or more and 40% by weight or less, based on the total weight of the binder solution (36) a metal precursor (36a); a thermoplastic binder (36b) comprising one or more thermoplastic polymer strands; a solvent in which the fugitive metal precursor (36a) and the thermoplastic binder (36b) are dissolved. Binder solution (36). (Additional note 2) 10. The binder solution (36) of claim 1, wherein the fugitive metal precursor (36a) is selected from the group consisting of alkaline earth metals, transition metals, post-transition metals, metalloids, rare earth metals, and combinations thereof. (Additional note 3) 3. The binder solution (36) of claim 1 or claim 2, wherein the fugitive metal precursor (36a) comprises an organometallic compound, the organometallic compound comprising ferrocene, cobaltocene, iron pentacarbonyl, or a combination thereof. (Additional note 4) 4. The binder solution (36) of any one of claims 1 to 3, wherein the fugitive metal precursor (36a) comprises a salt, the salt comprising a compound selected from the group consisting of carboxylates, nitrates, sulfates, carbonates, formates, chlorides, halides, derivatives thereof, and combinations thereof. (Additional note 5) 5. The binder solution (36) of any one of appendixes 1 to 4, wherein each of the one or more thermoplastic polymer strands is selected from the group consisting of polyvinyl alcohol (PVA), polyamide, polyacrylamide (PAAm), polymethyl methacrylate (PMMA), polyvinyl carbonate, derivatives thereof, and combinations thereof. (Additional note 6) 6. The binder solution (36) according to any one of appendix 1 to 5, wherein the viscosity of the binder solution is 1 cP or more and 40 cP or less. (Additional note 7) A method (10) for manufacturing a part, comprising: depositing a layer (22) of particulate material (24) on a working surface (32); selectively applying a binder solution (26) into the layer (22) of particulate material (24) in a pattern representing a layer of the component; The binder solution (36) 0.5% to 40% by weight of a fugitive metal precursor (36a), based on the total weight of the binder solution (36); a thermoplastic binder (36b) comprising one or more thermoplastic polymer strands; and solvent wherein the solvent is a solvent in which the fugitive metal precursor (36a) and the thermoplastic binder (36b) are dissolved; forming a plurality of layers (22) of particulate material (24) containing a binder solution (36) by repeating the deposition and selective application steps; curing the applied binder solution (36) in the plurality of layers (22) of particulate material (24) containing the applied binder solution (36) to evaporate the solvent, thereby forming a green body part (60); A method (10) comprising: (Additional note 8) 10. The method of claim 7, wherein the fugitive metal precursor (36a) comprises a salt selected from the group consisting of carboxylates, nitrates, sulfates, carbonates, formats, chlorides, halides, derivatives thereof, and combinations thereof. (Additional note 9) The particulate material (24) comprises a metal particulate material, the metal particulate material being nickel 10. The method of any one of clauses 7 or 8, comprising forming a metal alloy, a cobalt alloy, a cobalt chromium alloy, a titanium alloy, an aluminum-based material, a tungsten alloy, a stainless steel alloy, or a combination thereof. (Additional note 10) 10. The method (10) of claim 9, further comprising heating the green body part (60) at or above a first temperature in an oxygen-free environment to remove at least a portion of the thermoplastic binder (36b) and sinter at least a portion of the fugitive metal precursor (36a) so that the sintered fugitive metal precursor (36a) forms necked regions of the metal material (64) between the particulate material (24), thereby forming a Brown body part (62); and heating the Brown body part (62) to or above a second temperature to sinter the particulate material (24), thereby forming a consolidated part (70).

Claims

1. A green body part (60), a plurality of layers (22) of particulate material (24); 0.5% to 5% by weight of a fugitive metal precursor (36a) based on the total weight of the green body part (60); and a thermoplastic binder (36b) of 0.5% by weight or more and 3% by weight or less based on the total weight of the green body part (60), The fugitive metal precursor (36a) is a salt selected from the group consisting of nickel chloride, iron chloride, nickel formate, copper chloride, silver nitrate, nickel nitrate, nickel carbonate, silver carbonate, silver perchlorate, silver halide, nickel sulfate, nickel sulfamate, nickel oxalate dehydrate, ammonium molybdate tetrahydrate, aluminum nitrate, magnesium chloride, barium nitrate, barium chloride, titanium nitrate, and combinations thereof; an organometallic compound, wherein the organometallic compound comprises ferrocene, cobaltocene, iron pentacarbonyl, or a combination thereof; the thermoplastic binder (36b) includes first polymer strands including a first functional group and a second polymer strand including a second functional group different from the first functional group but complementary to the first functional group; The thermoplastic binder (36b) binds the particulate material (24) of the plurality of layers (22) of the particulate material (24).

2. 2. The green body part of claim 1, wherein the particulate material comprises a metal particulate material, the metal particulate material comprising a nickel alloy, a cobalt alloy, a cobalt chromium alloy, a titanium alloy, an aluminum-based material, a tungsten alloy, a stainless steel alloy, or a combination thereof.

3. 10. The green body part of claim 1, wherein the particulate material comprises a ceramic particulate material, the ceramic particulate material comprising alumina, aluminum nitride, zirconia, titania, silica, silicon nitride, silicon carbide, boron nitride, or combinations thereof.

4. 3. The green body part (60) of claim 1 or 2, wherein each of the first polymer strand and the second polymer strand is selected from the group consisting of polyvinyl alcohol (PVA), polyamide, polyacrylamide (PAAm), polymethyl methacrylate (PMMA), polyvinyl carbonate, derivatives thereof, and combinations thereof.

5. A brown body part (62), a plurality of layers (22) of particulate material (24); a fugitive metal precursor (36a), The fugitive metal precursor (36a) is a salt selected from the group consisting of nickel chloride, iron chloride, nickel formate, copper chloride, silver nitrate, nickel nitrate, nickel carbonate, silver carbonate, silver perchlorate, silver halide, nickel sulfate, nickel sulfamate, nickel oxalate dehydrate, ammonium molybdate tetrahydrate, aluminum nitrate, magnesium chloride, barium nitrate, barium chloride, titanium nitrate, and combinations thereof; and an organometallic compound, wherein the organometallic compound comprises ferrocene, cobaltocene, iron pentacarbonyl, or a combination thereof.

6. 6. The brown body component of claim 5, wherein the particulate material comprises a metallic particulate material, the metallic particulate material comprising a nickel alloy, a cobalt alloy, a cobalt chromium alloy, a titanium alloy, an aluminum-based material, a tungsten alloy, a stainless steel alloy, or a combination thereof.

7. 6. The brown body part of claim 5, wherein the particulate material comprises a ceramic particulate material, the ceramic particulate material comprising alumina, aluminum nitride, zirconia, titania, silica, silicon nitride, silicon carbide, boron nitride, or a combination thereof.

Images